An integrated semiconductor memory operates in synchronization with a
clock signal in a normal operating state and is switched from the normal
operating state to a test operating state by applying a combination of
control signals. During a first test cycle, selection transistors for
memory cells are turned on by asynchronously actuating the semiconductor
memory using a state change in a control signal. In a second test cycle,
the memory content of at least one of the previously activated memory
cells is read by synchronously actuating the semiconductor memory using a
second signal combination of control signals. By shifting the timing of a
signal edge which prompts the state change in the first test cycle close
to the time at which the second signal combination is applied in the
second test cycle, it is possible to test short reading times which are
within one period of the clock signal.